User interface for a portion of a display screen



FIG. 1 is a front view of a user interface for a portion of a display screen showing our new design; and,

FIG. 2 is an enlarged front view thereof, the user interface is shown separately for clarity of illustration.

The broken line showing of a portion of a display screen in FIG. 1 is for illustrative purposes only and forms no part of the claimed design. 

The ornamental design for a user interface for a portion of a display screen, as shown and described. 